Fearing biological attack, the U.S. military has vaccinated “multiple tens of thousands” of servicemembers against smallpox. But for weakened immune systems, it’s the live-virus vaccine that’s the terror. The new initiative has spurred a wave of HIV screening throughout the armed forces—prompting privacy worries for HIVers who, excused from being vaccinated, risk being “outed.”

Active servicemembers have long been tested for HIV, but many other personnel haven’t. The Navy, for example, bought 10,000 OraQuick HIV tests for Military Sealift Command (MSC) ships, staffed by civilians. Regulations assure confidentiality, but HIV results have been known to leak. Positive men may be assumed to be gay and face harassment, said Jeffrey Cleghorn, attorney for the Servicemembers Legal Defense Network. Frank Randall of MSC Public Affairs responded, “No one will know what specific contraindication any mariner has, only that there is one,” adding that sailors with skin conditions like eczema also skip the vax.

A smallpox vaccine called “modified vaccinia Ankara” (MVA) has proved safe for the immune-compromised—but its effectiveness has not. Health and Human Services awarded $20 million to two companies in February to test MVA; human trials begin next year. But until a safer vax can be found for all military employees, concerns about HIV testing and confidentiality will add extra stress to these uneasy times.